This invention relates to a disposable diaper for absorption and containment of body wastes.
Conventional open-type disposable diapers basically comprise a liquid-pervious topsheet, a liquid-impervious base sheet and a liquid-absorbent panel so as to configure, in a longitudinal direction, a front waist region, a rear waist region and a crotch region extending between these waist regions. Some of the diapers further comprise a pair of end flaps extending in a transverse direction immediately outside longitudinal opposite ends of the panel and a pair of side flaps extending in the longitudinal direction immediately outside transversely opposite side edges of the panel.
To wear the diaper, the side flaps in the rear waist region may be placed upon the outer side of the side flaps in the front waist region, then the respective tape fasteners may be anchored on the target tape strip to connect the front and rear waist regions with each other. Upon connection of the front and rear waist regions, a waist-hole and a pair of leg-holes are defined in the diaper. Such diaper is disclosed, for example, in Japanese Patent Application Publication Nos. 1998-24066A; 1998-24060A. and 1998-43234A.
In the conventional diaper as has been described above, body wastes must be immediately absorbed by the liquid-absorbent panel and contained therein in order to prevent the body wastes from leaking from the diaper. To this end, the inner surface of the diaper must be kept in contact with the wearer""s skin during use of the diaper. Here is an anxiety for such diaper that one of the front and rear waist regions of the diaper might slip down along the wearer""s waist as the wearer lying on the bedding moves in the longitudinal direction due to a frictional force generated between the diaper and the bedding. Should the front or rear waist region slip down, the inner surface of the diaper will be spaced apart from the wearer""s skin and it will be difficult for the panel to absorb the body wastes and prevent leakage thereof.
It is an object of this invention to provide a disposable diaper free from anxiety that the front waist region and/or the rear waist region might slip down along the wearer""s torso during use of the diaper and adapted to reliably absorb and contain body wastes in the liquid-absorbent panel.
According to this invention, there is provided a disposable diaper having a front waist region, a rear waist region and a crotch region extending therebetween comprising a substantially liquid-impervious base sheet, a liquid-absorbent panel placed onto the base sheet, a pair of end flaps extending in a transverse direction immediately outside longitudinal opposite ends of the panel and a pair of side flaps extending in a longitudinal direction immediately outside transversely opposite side edges of the panel.
The diaper further comprises at least one pleat defined by folding the base sheet and the panel together, the last least one pleat extending in the transverse direction across at least one of a front zone of the crotch region adjacent to the front waist region and a rear zone of the crotch region adjacent to the rear waist region so that the pleat has transversely opposite end regions thereof joined to the side flaps, respectively.
According to one embodiment of this invention, the pleat extends outward from an outer surface of the base sheet and is normally collapsed onto the end flaps.